Slotless stator coil device and brushless slotless motor

Abstract

The invention belongs to the technical field of motors, and particularly relates to a slotless stator coil device and a brushless slotless motor. The slotless stator coil device comprises a plurality of coil structures, and the plurality of coil structures are arranged in a surrounding manner along the circumferential direction to form a cylindrical structure; each coil structure comprises an insulating substrate and multiple layers of coil parts, each layer of coil part is provided with a first connecting end and a second connecting end, each layer of coil part is spirally arranged, the first connecting end is a spiral outer end of the coil part, and the second connecting end is a spiral inner end of the coil part; the first connecting end of the first-layer coil part is arranged to be a positive terminal or a negative terminal of the coil structure, the first connecting end or the second connecting end of the outermost-layer coil part is arranged to be a negative terminal or a positive terminal, and the multiple layers of coil parts are arranged in series. By applying the technical scheme, the problems of performance bottleneck and coil manufacturing difficulty of the miniature brushless slotless motor are solved, and the miniaturization design and even micromation design of the motor are realized.

Description

Technical Field

[0001] The present application belongs to the field of motor technology, and in particular relates to a slotless stator coil device and a brushless slotless motor. Background Art

[0002] The brushless slotless motor is a motor that uses electronic commutation technology. Compared with traditional brushed motors, it has higher efficiency, longer service life and lower noise. With the development and update of technology, the demand for small motors and even micro motors in many industries is increasing, and the market's requirements for miniaturized and even micro-miniaturized brushless slotless motors are constantly increasing.

[0003] In traditional brushless slotless motors, the stator winding is formed by winding copper wire or aluminum wire. Due to the volume limitation of copper wire or aluminum wire and the limitation of winding process, the miniaturization design of traditional brushless slotless motors has reached its limit. Summary of the invention

[0004] The purpose of the present application is to provide a slotless stator coil device and a brushless slotless motor, aiming to solve the problem of miniaturization or even micro-miniaturization design of brushless slotless motors in related technologies.

[0005] To achieve the above-mentioned purpose, according to the first aspect of the present application, the technical solution adopted in the present application is: a slotless stator coil device, comprising a plurality of coil structures, wherein the plurality of coil structures are arranged in a cylindrical structure along a circumferential direction;

[0006] Each coil structure includes an insulating substrate and a multi-layer coil portion stacked on the insulating substrate, each layer of the coil portion has a first connection end and a second connection end, each layer of the coil portion is spirally arranged by at least one line, the first connection end is the spiral outer end of the coil portion, the second connection end is the spiral inner end of the coil portion, and the spiral directions of two adjacent layers of the coil portion from the first connection end to the second connection end are opposite;

[0007] In the radial direction outward from the axis of the slotless stator coil device of the cylindrical structure, the first connection end of the first layer of coil parts is set as one of the positive terminal and the negative terminal of the coil structure, and the first connection end or the second connection end of the outermost layer of coil parts is set as the other of the positive terminal and the negative terminal of the coil structure. Between two adjacent layers of coil parts, the two first connection ends are electrically connected or the two second connection ends are electrically connected so that the multiple layers of coil parts are arranged in series, and an insulating layer is provided between two adjacent layers of coil parts.

[0008] Each coil structure of the slotless stator coil device provided in the embodiment of the present application includes an insulating substrate and a multi-layer coil portion stacked on the insulating substrate, so that each coil structure is formed into a sheet structure, which greatly reduces the overall thickness of the coil structure. The coil structure of the slotless stator coil device of the present application adopts a design structure of stacking and laying multi-layer coil portions on an insulating substrate, and the lines of each layer of coil portions are arranged in a spiral. Compared with the traditional stator winding, the lines of the coil portion of the coil structure of the slotless stator coil device of the present application can be laid and arranged more evenly and regularly, thereby reducing the space waste generated by the coil portion during the laying process. When multiple coil structures are arranged around the circumference to form a cylindrical structure, and when the slotless stator coil device of the present application has the same volume as the traditional stator winding, since the lines of the coil part of the coil structure of the slotless stator coil device of the present application can be laid and arranged more evenly and regularly, the slotless stator coil device of the present application can lay more turns of coils, that is, the slot full rate of the coil of the slotless stator coil device of the present application is higher (the slot full rate is an important parameter in the motor design, and a higher slot full rate can increase the power density and efficiency of the motor), thereby enhancing the electromagnetic induction intensity, which is conducive to improving the output power and torque of the brushless slotless motor using the slotless stator coil device. In other words, when the number of turns of the slotless stator coil device of the present application is equal to that of the coil of the traditional stator winding, the slotless stator coil device of the present application can greatly reduce the overall volume of the cylindrical structure, so that the volume of the stator of the brushless slotless motor using the slotless stator coil device is greatly reduced, and the overall volume of the brushless slotless motor is greatly reduced, thereby achieving the purpose of further miniaturization or even micro-miniaturization of the brushless slotless motor. Moreover, compared with the traditional stator winding, the slotless stator coil device of the present application has a coil structure whose coil portion design structure can be adapted to mass production using industrial production processes.

[0009] In some embodiments of the present application, in each coil structure, along the radial direction of the cylindrical structure, the projections of the first connection end and the second connection end of each layer of coil parts on the insulating substrate overlap.

[0010] In some embodiments of the present application, at least one circuit of each layer of coil parts is prepared by an additive process, and the cross-section of at least one circuit is rectangular, trapezoidal, or has an arc-shaped top (for example, similar to the cross-section of a bread).

[0011] In some embodiments of the present application, each coil structure includes n layers of coil parts, and n≥2m, where m is a positive integer.

[0012] In some embodiments of the present application, along the axial direction of the slotless stator coil device, the shape of each coil of each layer of coil parts is rectangular, diamond, polygonal, racetrack or olive.

[0013] In some embodiments of the present application, the line width of at least one line of each layer of coil parts in the routing direction is variably set, and in the same coil structure, the number of coil turns of any two layers of coil parts is equal or unequal.

[0014] In some embodiments of the present application, when the shape of each coil of each layer of coil parts is a racetrack shape, the insulating substrate is square, and each layer of coil parts includes a plurality of straight sections along the length direction of the insulating substrate and a plurality of variable diameter sections located at both ends of the insulating substrate. The lengths of the plurality of straight sections are equal, and the line width of the straight sections is greater than, equal to or less than the line width of the variable diameter sections.

[0015] In some embodiments of the present application, in the same coil structure, the line thickness of at least one line of any two layers of coil parts is equal or unequal.

[0016] In some embodiments of the present application, along the radial direction of the cylindrical structure from the axis of the cylindrical structure to the outside, the line thickness of the multi-layer coil part of each coil structure gradually increases.

[0017] In some embodiments of the present application, the slotless stator coil device further includes an iron core tube, which is sleeved and fixed outside the cylindrical structure, and the iron core tube is formed by stacking a plurality of annular magnetic material sheets.

[0018] In some embodiments of the present application, the cylindrical structure is composed of multiple layers of cylinders that are sequentially nested, and the number of multiple coil structures in each layer of cylinder is equal; along the radial direction of the cylindrical structure, the multiple coil structures between two adjacent layers of cylinders are arranged opposite to each other in a one-to-one correspondence, or the multiple coil structures between any two adjacent layers of cylinders are circumferentially staggered by a predetermined angle in the same direction.

[0019] In some embodiments of the present application, the coil structure is provided with a stepped edge. Along the radial direction of the cylindrical structure, the stepped edge enables the coil structure to form a first coil portion and a second coil portion with a height difference, and the height of the stepped edge is equal to the thickness of the coil structure. Among two coil structures adjacent to each other along the circumference of the cylindrical structure, the first coil portion of one coil structure is stacked with the second coil portion of the other coil structure, and multiple coil structures are connected end to end to form a cylindrical structure.

[0020] According to a second aspect of the present application, there is provided a brushless slotless motor, characterized in that it comprises:

[0021] A housing having an assembly space;

[0022] As in the aforementioned slotless stator coil device, the slotless stator coil device is accommodated in the assembly space;

[0023] Two bearings are mounted on the housing, and the two bearings are respectively located at two ends of the slotless stator coil device;

[0024] The rotor assembly is rotatably inserted into the slotless stator coil device, and two ends of the rotor assembly are respectively installed on two bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of the three-dimensional structure of a slotless stator coil device according to an embodiment of the present application;

[0027] Figure 2 for Figure 1 A schematic top view of a slotless stator coil device along its axis is shown;

[0028] Figure 3 for Figure 1 A schematic diagram of the three-dimensional structure of the cylindrical structure of the slotless stator coil device is shown;

[0029] Figure 4 for Figure 3 The schematic top view of the cylindrical structure along its axial direction is shown;

[0030] Figure 5 for Figure 1 A schematic structural diagram of one layer of coil parts of the coil structure of the slotless stator coil device is shown;

[0031] Figure 6 for Figure 1 The three-dimensional structure diagram of the coil structure of the slotless stator coil device is shown Figure 1 ;

[0032] Figure 7 for Figure 1 The three-dimensional structure diagram of the coil structure of the slotless stator coil device is shown Figure 2 ;

[0033] Figure 8 A schematic diagram of the three-dimensional structure of another slotless stator coil device according to an embodiment of the present application;

[0034] Fig. 9 for Figure 8 A schematic top view of a slotless stator coil device along its axis is shown;

[0035] Fig.10 The three-dimensional structure of the brushless slotless motor of the embodiment of the present application is shown in FIG. Figure 1;

[0036] Fig.11 for Fig.10 The three-dimensional structure of the brushless slotless motor shown Figure 2 ;

[0037] Fig.12 for Fig.10 A schematic front view of a brushless slotless motor is shown;

[0038] Fig.13 for Fig.10 An exploded schematic diagram of a brushless slotless motor is shown;

[0039] Fig.14 for Fig.11 An exploded schematic diagram of a brushless slotless motor is shown;

[0040] Fig.15 for Fig.12 Schematic cross-sectional view along the AA direction.

[0041] Among them, the reference numerals in the figures are:

[0042] 100. Slotless stator coil device;

[0043] 10. Cylindrical structure; 11. Inner cylinder; 12. Outer cylinder; 13. Connecting part;

[0044] 20. Coil structure; 21. Insulating substrate; 22. Coil portion; 221. First connecting end; 222. Second connecting end; 223. Straight section; 224. Variable diameter section; 23. Step edge; 24. First coil portion; 25. Second coil portion;

[0045] 30. Iron core tube; 31. Magnetic material sheet;

[0046] 41. Positive electrode pad; 42. Negative electrode pad;

[0047] 200, brushless slotless motor;

[0048] 210, housing; 211, housing body; 212, end cover; 213, assembly space; 214, wire outlet;

[0049] 220, bearings;

[0050] 230. Rotor assembly; 231. Core shaft; 232. Permanent magnet. DETAILED DESCRIPTION

[0051] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0052] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0053] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0054] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] like Figures 1 to 9As shown, the slotless stator coil device 100 provided in the embodiment of the present application includes a plurality of coil structures 20, and the plurality of coil structures 20 are arranged around the cylindrical structure 10 along the circumferential direction. Each coil structure 20 includes an insulating substrate 21 and a multi-layer coil portion 22 stacked on the insulating substrate 21, each layer of the coil portion 22 has a first connection end 221 and a second connection end 222, each layer of the coil portion 22 is spirally arranged by at least one line, the first connection end 221 is the spiral outer end of the coil portion 22, the second connection end 222 is the spiral inner end of the coil portion 22, and the spiral directions of the two adjacent layers of the coil portion 22 from the first connection end 221 to the second connection end 222 are opposite. In the radial direction outward from the axis of the slotless stator coil device 100 of the tubular structure 10, the first connection end 221 of the first layer coil portion 22 is set as one of the positive terminal and the negative terminal of the coil structure 20, and the first connection end 221 or the second connection end 222 of the outermost layer coil portion 22 is set as the other of the positive terminal and the negative terminal of the coil structure 20. Between two adjacent layers of coil portions 22, the two first connection ends 221 are electrically connected or the two second connection ends 222 are electrically connected so that the multiple layers of coil portions 22 are arranged in series, and an insulating layer is provided between two adjacent layers of coil portions 22, that is, the remaining stacking positions between two adjacent layers of coil portions 22 are all insulated.

[0056] Each coil structure 20 of the slotless stator coil device 100 provided in the embodiment of the present application includes an insulating substrate 21 and a multi-layer coil portion 22 stacked on the insulating substrate 21, so that each coil structure 20 is formed into a sheet structure, which greatly reduces the overall thickness of the coil structure 20. The coil structure 20 of the slotless stator coil device 100 of the present application adopts a design structure in which multiple layers of coil portions 22 are stacked and laid on the insulating substrate 21, and the circuits of the coil portions 22 of each layer are arranged in a spiral. Compared with the traditional stator winding, the circuits of the coil portions 22 of the coil structure 20 of the slotless stator coil device 100 of the present application can be laid and arranged more evenly and regularly, thereby reducing the space waste generated by the coil portions 22 during the laying process. When a plurality of coil structures 20 are arranged circumferentially around a cylindrical structure 10, and when the slotless stator coil device 100 of the present application has the same volume as a traditional stator winding, since the lines of the coil portion 22 of the coil structure 20 of the slotless stator coil device 100 of the present application can be laid and arranged more evenly and regularly, the slotless stator coil device 100 of the present application can lay more turns of coils, that is, the slotless stator coil device 100 of the present application has a higher slot fill rate (the slot fill rate is an important parameter in motor design, and a higher slot fill rate can increase the power density and efficiency of the motor), thereby enhancing the electromagnetic induction intensity, which is beneficial to improving the output power and torque of the brushless slotless motor 200 using the slotless stator coil device 100. In other words, when the number of turns of the slotless stator coil device 100 of the present application is equal to that of the coil of the traditional stator winding, the slotless stator coil device 100 of the present application can greatly reduce the overall volume of the cylindrical structure 10, so that the volume of the stator of the brushless slotless motor 200 using the slotless stator coil device 100 is greatly reduced, and the overall volume of the brushless slotless motor 200 is greatly reduced, thereby achieving the purpose of further miniaturization or even micro-miniaturization of the brushless slotless motor 200. Moreover, compared with the traditional stator winding, the design structure of the coil part 22 of the coil structure 20 of the slotless stator coil device 100 of the present application can be adapted to the industrial production process for batch manufacturing.

[0057] Here, “each layer of coil part 22 is formed by at least one line in a spiral arrangement” means that each layer of coil part 22 can be formed by only one line in a spiral arrangement, or can be formed by multiple lines in a spiral arrangement. When each layer of coil part 22 is formed by multiple lines in a spiral arrangement, it is called a multi-strand parallel winding forming method, such as a double-strand parallel winding, a triple-strand parallel winding, etc.

[0058] In some embodiments of the present application, in each coil structure 20 of the slotless stator coil device 100, along the radial direction of the cylindrical structure 10, the projections of the first connection end 221 and the second connection end 222 of each layer of coil part 22 on the insulating substrate 21 overlap. Since the projections of the first connection end 221 and the second connection end 222 of the multi-layer coil part 22 on the insulating substrate 21 along the radial direction of the cylindrical structure 10 overlap, that is, the overlap degree of the first connection end 221 and the second connection end 222 of the multi-layer coil part 22 is high, when each layer of coil part 22 is formed on the insulating substrate 21, it is convenient to electrically connect the two first connection ends 221 or the two second connection ends 222 between two adjacent layers of coil parts 22. Further, along the radial direction of the cylindrical structure 10, the projections of all coils of each layer of coil part 22 on the insulating substrate 21 all overlap. When forming each layer of coil parts 22, each layer of coil parts 22 is formed on the insulating substrate 21 using a semiconductor process technology. Therefore, in a coil structure 20, the initially formed multi-layer coil parts 22 are separated from each other and completely insulated. In this way, when two adjacent layers of coil parts 22 are formed, it is necessary to punch holes at the positions of the first connection end 221 and the second connection end 222 between the two adjacent layers of coil parts 22 and sink conductors into the holes, that is, to form conductive vias (commonly known as via holes), so that the two first connection ends 221 between the two adjacent layers of coil parts 22 are electrically connected or the two second connection ends 222 are electrically connected, and finally the multi-layer coil parts 22 are arranged in series. Since the projections of the first connection end 221 and the second connection end 222 of the multi-layer coil part 22 on the insulating substrate 21 along the radial direction of the cylindrical structure 10 are overlapped, this greatly improves the accuracy of the punching process, thereby greatly improving the product yield and helping to reduce manufacturing costs.

[0059] In the process of forming each layer of coil part 22 by semiconductor process technology, the circuit of each layer of coil part 22 is prepared by additive process. When forming the first layer of coil part 22 on the insulating substrate 21, a layer of photoresist is first coated on the surface of the insulating substrate 21, and then the coil part 22 is projected on the photoresist, and a coil-shaped sink groove of the coil part 22 is formed on the insulating substrate 21 by laser engraving, UV photoetching and other steps, and then a layer of seed copper is sputtered in the sink groove by sputtering process, and then the coil circuit of the coil part 22 is additively formed on the basis of the seed copper by electroplating process. Among them, the combination of sputtering process and electroplating process is referred to as additive process. In addition, in the coil structure 20 of the slotless stator coil device of the embodiment of the present application, the cross-section of the circuit of each layer of coil part 22 is rectangular, trapezoidal or has an arc-shaped cross-section at the top (for example, similar to the cross-section of bread). That is to say, when the additively manufactured coil just fills the sink, and the cross-sectional shape of the sink is rectangular or trapezoidal, the cross-sectional shape of the line of the coil portion 22 is the same as the cross-sectional shape of the sink, which is rectangular or trapezoidal. When the additively manufactured coil does not fill the sink or slightly exceeds the sink, at this time, the top of the line of the coil portion 22 is arc-shaped during the additive process, that is, the top of the cross-sectional shape of the line is arc-shaped. After the first layer of coil portion 22 is formed, the second layer of coil portion 22 is formed, and the forming process is the same as the forming process of the first layer of coil portion 22. Then, a layer of photoresist coated on the first layer of coil portion 22 is the insulating layer between the two adjacent layers of coil portions 22. And so on, thereby preparing and forming a stacked multi-layer coil portion 22.

[0060] Furthermore, when the semiconductor process is used to form each layer of coil parts 22 on the insulating substrate 21, the insulating substrate 21 is in a flat state, that is, each layer of coil parts 22 is formed on a plane, which not only reduces the difficulty of forming each layer of coil parts 22 using the semiconductor process, but also greatly reduces the difficulty of punching, and improves the accuracy of the electrical connection between the two first connection ends 221 or the electrical connection between the two second connection ends 222 of the adjacent two layers of coil parts 22. After the preparation of multiple coil structures 20, each coil structure 20 is bent into an arc shape with a predetermined arc angle, so that the multiple coil structures 20 are arranged around the cylindrical structure 10 in the circumferential direction. In addition, the outer wall of the cylindrical structure 10 is coated with an insulating protective film, which can protect the outer wall of the cylindrical structure 10 to avoid damaging the outer wall of the cylindrical structure 10 when the cylindrical structure 10 is moved, and can basically shape the cylindrical structure 10 to avoid the multiple coil structures 20 of the cylindrical structure 10 from loosening and detaching.

[0061] In the slotless stator coil device 100 of some embodiments of the present application, each coil structure 20 includes n layers of coil parts 22, and n≥2m, where m is a positive integer. That is, the number of layers of the coil parts 22 of the coil structure 20 of the slotless stator coil device 100 can be an even number of layers such as 2, 4, 6, 8, 10, etc. In each coil structure 20, when the multiple layers of coil parts 22 are arranged in series, along the radial direction of the cylindrical structure 10 from the axis of the slotless stator coil device 100 to the outside, the first connection end 221 of the first layer of coil parts 22 is set as one of the positive terminal of the coil structure 20 (that is, the first connection end 221 of the first layer of coil parts 22 is connected to the positive electrode pad 41 as the positive terminal) and the negative terminal (that is, the first connection end 221 of the first layer of coil parts 22 is connected to the negative electrode pad 42 as the negative terminal), and the first connection end 221 of the outermost layer of coil parts 22 is set as the other of the positive terminal and the negative terminal of the coil structure 20. In the present application, the first connection end 221 of the first layer coil part 22 is connected to the positive electrode pad 41 as the positive terminal, and the first connection end 221 of the outermost layer coil part 22 is connected to the negative electrode pad 42. In this way, the positive electrode pad 41 of the coil structure 20 and the first connection end 221 of the first layer coil part 22 can be directly connected by wire, and the negative electrode pad 42 of the coil structure 20 and the first connection end 221 of the outermost layer coil part 22 can also be directly connected by wire, and the lead wire between the first connection end 221 of the first layer coil part 22 and the positive electrode pad 41 and the lead wire between the first connection end 221 of the outermost layer coil part 22 and the negative electrode pad 42 are both located on the same side of the insulating substrate 21, which optimizes the wiring design of the coil structure 20 and reduces the wiring difficulty.

[0062] Preferably, in the slotless stator coil device 100 of the embodiment of the present application, each coil structure 20 includes four layers of coil parts 22 (ie, m=2).

[0063] In the slotless stator coil device 100 of other embodiments of the present application, the number of layers of the coil part 22 of each coil structure 20 may also be an odd number of layers, that is, an odd number of layers such as 1, 3, 5, 7, 9, etc. At this time, in each coil structure 20, when the multiple layers of coil parts 22 are arranged in series, along the radial direction of the cylindrical structure 10 from the axis of the slotless stator coil device 100 to the outside, the first connection end 221 of the first layer of coil parts 22 is set to one of the positive terminal or the negative terminal of the coil structure 20, and the second connection end 222 of the outermost layer of coil parts 22 is set to the other of the positive terminal and the negative terminal of the coil structure 20 (the first connection end 221 of the first layer of coil parts 22 is set to the positive terminal of the coil structure 20, and the second connection end 222 of the outermost layer of coil parts 22 is set to the negative terminal of the coil structure 20 as an example for explanation). In this embodiment, the positive electrode pad 41 of the coil structure 20 and the first connection end 221 of the first layer coil part 22 can be directly connected electrically by wires. However, when the second connection end 222 of the outermost layer coil part 22 is connected to the negative electrode pad 42, it is necessary to punch a hole in the second connection end 222 of the outermost layer coil part 22 and pass through the insulating substrate 21, then sink the conductor into the hole, and then connect the wires to the negative electrode pad 42 on the other side of the insulating substrate 21 away from the coil part 22. In other words, the wires between the first connection end 221 of the first layer coil part 22 and the positive electrode pad 41 and the wires between the second connection end 222 of the outermost layer coil part 22 and the negative electrode pad 42 are located on both sides of the insulating substrate 21, respectively.

[0064] In the slotless stator coil device of some embodiments of the present application, along the axial direction of the slotless stator coil device, the shape of each spiral coil of each layer of coil part 22 is rectangular, rhombus, polygonal, racetrack or olive. The polygon is a polygon including hexagons and above, preferably a regular polygon.

[0065] In the slotless stator coil device of some embodiments of the present application, the line width of each layer of coil parts 22 of the coil structure 20 in the routing direction is variably set. That is, while keeping the total resistance of each layer of coil parts 22 basically unchanged, the line width of each layer of coil parts 22 can be increased or reduced at any position to meet the actual routing requirements. Moreover, in the same coil structure 20, the number of coil turns of any two layers of coil parts 22 can be equal or unequal. In the embodiment of the present application, in the same coil structure 20, the number of coil turns of any two layers of coil parts 22 is preferably equal.

[0066] like Figures 5 to 7As shown, in some embodiments of the present application, when the shape of each coil of each layer of coil part 22 is in the shape of a racetrack, the insulating substrate 21 of each coil structure 20 is in a square shape along the axial direction of the slotless stator coil device 100. In each coil structure 20, each layer of coil part 22 includes a plurality of straight sections 223 along the length direction of the insulating substrate 21 and a plurality of variable diameter sections 224 located at both ends of the insulating substrate 21, wherein the length direction of the insulating substrate 21 is parallel to the axial direction of the slotless stator coil device 100. When the coil parts 22 of each layer of the coil structure 20 are energized to generate a magnetic field, the range of the effective magnetic field is not the entire magnetic field range generated by the coil part 22, but mainly the magnetic field range generated by the plurality of straight sections 223, and the magnetic field range generated by the plurality of variable diameter sections 224 located at both ends of the insulating substrate 21 has a relatively minor effect on the magnetic induction effect on the rotor assembly 230 compared with the magnetic field range generated by the plurality of straight sections 223. In each layer of coil parts 22 of each coil structure 20 of the slotless stator coil device 100, the lengths of the plurality of straight sections 223 are all equal. Thus, the range of the effective magnetic field generated when each layer of coil parts 22 is energized is increased. When the brushless slotless motor 200 is equipped with the slotless stator coil device 100, the range of the effective magnetic field that effectively acts on the rotor assembly 230 of the brushless slotless motor 200 is increased, thereby effectively improving the output efficiency of the brushless slotless motor 200 and improving the product quality of the brushless slotless motor 200.

[0067] The line width of the straight segment 223 is greater than, equal to, or less than the line width of the variable diameter segment 224. In order to further improve the magnetic induction effect of the magnetic field range generated by the multiple straight segments 223 on the rotor assembly 230, therefore, the present application preferably has a line width of the straight segment 223 greater than the line width of the variable diameter segment 224. In this way, the length of the multiple straight segments 223 on the insulating substrate 21 can be maximized, that is, the length of the multiple straight segments 223 is increased, and the length of the area occupied by the variable diameter segment 224 at the end position of the insulating substrate 21 is reduced, so that the magnetic field range generated by the multiple straight segments 223 on the rotor assembly 230 is close to the maximum.

[0068] Furthermore, although the length of the straight section 223 with a wider line width increases, the length of the reduced diameter section 224 decreases accordingly. Furthermore, the line width of the reduced diameter section 224 is smaller than the line width of the straight section 223, so that the resistance of each layer of the coil portion 22 can be kept unchanged, so that the heat generated by each layer of the coil portion 22 does not increase. This is conducive to ensuring the overall thermal performance of the slotless stator coil device 100, ensuring the effective working time of the slotless stator coil device 100, and extending the service life of the slotless stator coil device 100.

[0069] Furthermore, when the line width of the reduced diameter section 224 is smaller than the line width of the straight section 223, when the spiral wiring is performed on each layer of the coil portion 22, the height of the plurality of reduced diameter sections 224 located at both ends of the insulating substrate 21 along the length direction of the insulating substrate 21 can be effectively reduced. This is conducive to reducing the overall length of the coil structure 20 along the axial direction of the slotless stator coil device 100.

[0070] In some embodiments of the present application, in the same coil structure 20 , the circuit thicknesses of any two layers of coil parts 22 may be equal or unequal.

[0071] When the line thickness of any two layers of coil parts 22 in the same coil structure 20 is not equal, in the slotless stator coil device 100 of some embodiments of the present application, the line thickness of the multi-layer coil parts 22 of each coil structure 20 gradually increases along the radial direction of the cylindrical structure 10 from the axis of the cylindrical structure 10 to the outside. That is to say, in the multi-layer coil parts 22 of each coil structure 20, along the radial direction of the cylindrical structure 10 from the axis of the cylindrical structure 10 to the outside, the closer to the axis of the cylindrical structure 10, the higher the coil density of the coil part 22. In this way, the magnetic field generated by the coil part 22 can effectively enhance the magnetic induction effect on the rotor assembly 230 of the brushless slotless motor 200, and improve the output power and torque of the brushless slotless motor 200. In addition, the design structure of the gradually increasing line thickness of the multi-layer coil parts 22 of each coil structure 20 can keep the resistance of each layer of the coil part 22 unchanged, so that the heat generation of each layer of the coil part 22 will not increase. This is beneficial to improving the overall thermal performance of the slotless stator coil device 100 , ensuring the effective working time of the slotless stator coil device 100 , and is beneficial to extending the service life of the slotless stator coil device 100 .

[0072] In some embodiments of the present application, the cylindrical structure 10 is composed of multiple layers of cylinders that are sequentially sleeved, and the number of multiple coil structures 20 in each layer of cylinder is equal. In addition, along the radial direction of the cylindrical structure 10, the multiple coil structures 20 between two adjacent layers of cylinders are arranged one by one in a corresponding manner. In the multi-phase motor of this embodiment, such as a three-phase motor, each layer of cylinder is formed by three coil structures 20 surrounding the circumference, and each phase is composed of multiple coil structures 20 along the radial direction of the cylindrical structure 10, so that the number of winding turns of each phase is increased, thereby increasing the intensity of the generated magnetic field, effectively enhancing the magnetic induction effect of the magnetic field generated by the coil part 22 on the rotor assembly 230 of the brushless slotless motor 200, and improving the output power and torque of the brushless slotless motor 200.

[0073] In some embodiments of the present application, the cylindrical structure 10 is composed of multiple layers of cylinders that are sequentially sleeved, and the number of the multiple coil structures 20 in each layer of cylinder is equal. In addition, the multiple coil structures 20 between any two adjacent layers of cylinders are circumferentially staggered by a predetermined angle in the same direction. Figure 8 and Fig. 9 As shown, in some embodiments of the present application, the cylindrical structure 10 includes an inner cylinder 11 and an outer cylinder 12 sleeved on the inner cylinder 11, that is, the cylindrical structure 10 is composed of two layers of sleeved cylinders. The number of multiple coil structures 20 of the inner cylinder 11 is equal to the number of multiple coil structures 20 of the outer cylinder 12, and two adjacent coil structures 20 are connected by a connecting portion 13, and the multiple coil structures 20 of the inner cylinder 11 and the multiple coil structures 20 of the outer cylinder 12 are staggered in the circumferential direction. For example, each layer of cylinder is formed by three coil structures 20 surrounding the circumference, and the central angle corresponding to each coil structure 20 is 120°. Then, the predetermined rotation angle of the outer cylinder 12 staggered in the circumferential direction relative to the inner cylinder 11 is 60°. In this way, the cylindrical structure 10 formed by the sleeve of the inner cylinder 11 and the outer cylinder 12 actually has six phases.

[0074] In the slotless stator coil device 100 of the present application, the number of coil structures 20 of the cylindrical structure 10 can be 3, 6, 9, 12, etc., that is, an integer multiple of 3 coil structures 20. These coil structures 20 are equally divided into multiple parts, each of which is surrounded to form a layer of cylinder, and then multiple layers of cylinders are sequentially sleeved to form the cylindrical structure 10.

[0075] In some embodiments of the present application, Figure 6 and Figure 7 As shown, the coil structure 20 is provided with a step edge 23. In the radial direction of the cylindrical structure 10, the step edge 23 enables the coil structure 20 to form a first coil portion 24 and a second coil portion 25 with a height difference, and the height of the step edge 23 is equal to the thickness of the coil structure 20. Figure 3 and Figure 4 As shown, in two coil structures 20 adjacent to each other in the circumferential direction of the cylindrical structure 10, the first coil portion 24 of one coil structure 20 is stacked with the second coil portion 25 of the other coil structure 20, and the multiple coil structures 20 are connected end to end to form the cylindrical structure 10. In the multi-phase motor of this embodiment, the multiple coil structures 20 are mutually overlapped and connected end to end through the stepped edges 23, and actually form two layers of cylinders, and in this way, the cylindrical structure 10 formed by the multiple coil structures 20 in the circumferential direction is more stable.

[0076] like Figure 1 and Figure 2As shown, in some embodiments of the present application, the slotless stator coil device 100 also includes an iron core barrel 30, which is sleeved and fixed outside the cylindrical structure 10. The iron core barrel 30 can effectively guide and concentrate the magnetic field to form a magnetic circuit, improve the electromagnetic performance, and can efficiently generate and transmit electromagnetic energy. The iron core barrel 30 can also provide mechanical support for the cylindrical structure 10, can withstand the electromagnetic force and mechanical force generated when the brushless slotless motor 200 is running, and prevent the cylindrical structure 10 from being damaged due to vibration or impact. In addition, the iron core barrel 30 is sleeved and fixed outside the cylindrical structure 10, which is conducive to heat dissipation of the cylindrical structure 10, and can effectively reduce the temperature rise of the brushless slotless motor 200 when it is running. The iron core barrel 30 includes a plurality of magnetic material sheets 31, and the plurality of magnetic material sheets 31 are sequentially stacked and formed along the axial direction of the slotless stator coil device 100, and the two adjacent magnetic material sheets 31 are insulated. The core tube 30 formed by stacking multiple magnetic material sheets 31 can reduce eddy current loss and hysteresis loss when the coil part 22 of the coil structure 20 is energized to generate a magnetic field. The magnetic material sheets 31 include but are not limited to silicon steel sheets, amorphous material sheets, iron sheets, etc.

[0077] According to another aspect of the present application, a brushless slotless motor 200 is provided. Figures 10 to 15 As shown, the brushless slotless motor 200 includes a housing 210, a rotor assembly 230, two bearings 220 and the aforementioned slotless stator coil device 100. The housing 210 includes a housing body 211 and an end cover 212. The end cover 212 covers one end of the housing body 211 to form an assembly space 213. The slotless stator coil device 100 is accommodated in the assembly space 213. In addition, the wires led out from the positive electrode pad 41 and the negative electrode pad 42 of each coil structure 20 pass through the outlet 214 of the housing 210. The led wires are used to be electrically connected to the electronic commutation mechanism. And, as Figures 13 to 15 As shown, two bearings 220 are installed on the housing 210, and the two bearings 220 are respectively located at the two ends of the slotless stator coil device 100, that is, one bearing 220 is installed on the end cover 212, and the other bearing 220 is installed on the other end of the housing body 211 away from the end cover. Figures 13 to 15As shown, the rotor assembly 230 includes a core shaft 231 and a permanent magnet 232. The permanent magnet 232 is fixedly sleeved on the core shaft 231. The permanent magnet 232 can be rotatably inserted into the slotless stator coil device 100, and the two ends of the core shaft 231 are respectively installed on two bearings 220. Among them, at least one end of the core shaft 231 serves as the output end of the motor, and the motor output end can be an end of the core shaft 231 that passes through the housing 210; or, the motor output end can also be located in the housing 210. One end of the core shaft 231 passes through the end of the shell body 211 away from the end cover 212 as the single output end of the motor, and the motor is a single-head motor at this time; or, one end of the core shaft 231 passes through the end of the shell body 211 away from the end cover 212 as one of the output ends, and the other end of the core shaft 231 passes through the end cover 212 as the other output end, and the motor is a double-head motor at this time.

[0078] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A slotless stator coil device, characterized in that: It comprises a plurality of coil structures, wherein the plurality of coil structures are arranged circumferentially around a cylindrical structure; Each of the coil structures comprises an insulating substrate and a multi-layer coil portion stacked on the insulating substrate, each layer of the coil portion has a first connection end and a second connection end, each layer of the coil portion is spirally arranged by at least one line, the first connection end is the spiral outer end of the coil portion, the second connection end is the spiral inner end of the coil portion, and the spiral directions of the coil portions of two adjacent layers from the first connection end to the second connection end are opposite; In the radial direction from the axis of the slotless stator coil device along the cylindrical structure to the outside, the first connection end of the coil part of the first layer is set to be one of the positive terminal and the negative terminal of the coil structure, and the first connection end or the second connection end of the coil part of the outermost layer is set to be the other of the positive terminal and the negative terminal of the coil structure. Between two adjacent layers of the coil parts, the two first connection ends are electrically connected or the two second connection ends are electrically connected so that the multiple layers of coil parts are arranged in series, and an insulating layer is provided between two adjacent layers of the coil parts.

2. The slotless stator coil device according to claim 1, characterized in that: In each of the coil structures, along the radial direction of the cylindrical structure, projections of the first connection end and the second connection end of the coil portion of each layer on the insulating substrate overlap.

3. The slotless stator coil device according to claim 1, characterized in that: The at least one circuit of the coil part of each layer is prepared and formed by an additive process, and the cross section of the at least one circuit is rectangular, trapezoidal or has an arc-shaped top.

4. The slotless stator coil device according to claim 1, characterized in that: Each of the coil structures includes n layers of coil parts, and n≥2m, wherein m is a positive integer.

5. The slotless stator coil device according to claim 1, characterized in that: Along the axial direction of the slotless stator coil device, each coil of the coil portion of each layer has a shape of a rectangle, a rhombus, a polygon, a racetrack or an olive.

6. The slotless stator coil device according to claim 5, characterized in that: The line width of at least one line of the coil part of each layer in the routing direction is variably set, and in the same coil structure, the number of coil turns of any two layers of the coil part is equal or unequal.

7. The slotless stator coil device according to claim 6, characterized in that: When the shape of each coil of the coil portion of each layer is in the shape of a racetrack, the insulating substrate is square, and the coil portion of each layer includes a plurality of straight sections along the length direction of the insulating substrate and a plurality of variable diameter sections located at both ends of the insulating substrate, the lengths of the plurality of straight sections are equal, and the line width of the straight section is greater than, equal to or less than the line width of the variable diameter section.

8. The slotless stator coil device according to claim 5, characterized in that: In the same coil structure, the circuit thickness of the at least one circuit of any two layers of the coil parts is equal or unequal.

9. The slotless stator coil device according to claim 8, characterized in that: In a radial direction of the cylindrical structure from the axis of the cylindrical structure to the outside, the line thickness of the multilayer coil part of each coil structure gradually increases.

10. The slotless stator coil device according to claim 1, characterized in that: The slotless stator coil device further comprises an iron core barrel, which is sleeved and fixed outside the cylindrical structure, and the iron core barrel is formed by stacking a plurality of annular magnetic material sheets.

11. The slotless stator coil device according to any one of claims 1 to 10, characterized in that: The cylindrical structure is composed of multiple layers of cylinders that are sequentially sleeved, and the number of the multiple coil structures in each layer of the cylinder is equal; In the radial direction of the cylindrical structure, the multiple coil structures between two adjacent layers of the cylinder are arranged opposite to each other in a one-to-one correspondence, or the multiple coil structures between any two adjacent layers of the cylinder are circumferentially staggered by a predetermined angle in the same direction.

12. The slotless stator coil device according to any one of claims 1 to 10, characterized in that: The coil structure is provided with a stepped edge. In the radial direction of the cylindrical structure, the stepped edge enables the coil structure to form a first coil part and a second coil part with a height difference, and the height of the stepped edge is equal to the thickness of the coil structure. In two coil structures adjacent to each other in the circumferential direction of the cylindrical structure, the first coil part of one coil structure is stacked with the second coil part of the other coil structure, and a plurality of the coil structures are connected end to end to form the cylindrical structure.

13. A brushless slotless motor, characterized in that: include: A housing having an assembly space; The slotless stator coil device according to any one of claims 1 to 12, wherein the slotless stator coil device is accommodated in the assembly space; Two bearings are mounted on the housing, and the two bearings are respectively located at two ends of the slotless stator coil device; The rotor assembly is rotatably arranged in the slotless stator coil device, and two ends of the rotor assembly are respectively installed on the two bearings.

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